ABSTRACT
In this review modern concepts on the formation of specific immunity to listeriosis are presented. Numerous data indicate that in Listeria monocytogenes virulence and the capacity for inducing specific protection is ensured by the protein listeriolysin O. The importance of gamma-interferon, tumor necrosis factor alpha, interleukin 12 and other mediators in ensuring the differentiation of (CD4(+) T-cells into Th1-helpers and cytotoxic T-lymphocytes in animals infected with L. monocytogenes is described in detail. The safety and effective preparations for specific prophylaxis of listeriosis were not developed. Hopeful results have been obtained in experiments on the immunization of mice with killed bacteria with listeriolysin O or interleukin 12. Works describing the use of modified L. monocytogenes strains as vectors for the creation of vaccines against different infections seem to show good prospects.
Subject(s)
Bacterial Toxins , Listeria monocytogenes/immunology , Listeriosis/immunology , Animals , Heat-Shock Proteins/immunology , Hemolysin Proteins , Humans , Immunity , Listeria monocytogenes/pathogenicity , Listeriosis/prevention & control , Mice , Rabbits , VirulenceABSTRACT
The DNA-DNA hybridization method was used to study 4 species of bacteria of the genus Listeria. Concerning the DNA homology, L. monocytogenes strains may be divided into several species (in particular, the pathogenic forms may be isolated into independent taxon), in correlation with their biochemical and serological properties. Most of the studied strains of this species exhibit a high level of DNA homology--65-100%. Bacteria of the L. grayi and L. murrayi species are closely related to each other (90% of DNA homology), the reasonable suggestion being to unite them into a single species. L. denitrificans has 7% of DNA homology with the DNA of the other three species suggesting that it should be excluded from the genus Listeria.
Subject(s)
Base Sequence , DNA, Bacterial/genetics , Listeria/classification , Nucleic Acid Hybridization , Sequence Homology, Nucleic Acid , Listeria/genetics , Species SpecificityABSTRACT
The optimum conditions for performing the phage titer increase test aimed at the detection of Listeria in water and soil have been established.
